Airdome type pulsator for fuel pumps



Feb. 14, 1933. A. M. BABITCH AIRDOME TYPE PULSATOR EUR FUEL PUMPS Filed Sept.. 20, 1929 In endin application Ser. 20 filed ISB g 35 tioned as to 50 a wrench.

Patented Feb. 14, 1933 I ABRAHAM M. marron, or FLINT,

MICHIGAN AIBDOME TYPE PULSATOB FOB FUEL PUMPS Application med september 2o, i929. serial no. 393,974.

This invention relates to simple and advantageous means, relying upon the elasticity of a conned body ofair or vapors and upon a -novel self-replenishment effect, for augmenting the delivery of a liquid fuel from a diaphragm pump, or the like; and all forms of t is invention may involve (l) the use of a bubble-receiving and air-confining dome elea bubble-collecting v said dome,-the"aggregate cross-sectional area of openings which provide this throat being preferably about one-eighth of the cross-sectional area of the dome.

ebruary 15, 1928, there is disclosure of an early embodiment of the resent lnvention; and Fig. 1 of the present rawing is reproduced from the mentioned application; but more recent and etlicient and 1nexpens1ve embodiments of said invention are also herein disclosed. preferably include a threaded body element which may serve as a valve plug andwhich is formed separate from an air-dome element but secured in air-tight relationship thereto,said body element, or 'a partition or subsidiary element, providing the 'mentioned throat; and said throat preferably provides a plurality of openings so formed and posifavor a rise of bubbles therethrough from a bubble-collecting chamber abovean outlet valve, for a self-replenishment of the air in said dome.

Functionally, the pulsators herein, de-

- scribed and claimedu resemble the diaphragm pulsator or so-called auxiliary means described andclaimed in patent application phragm pulsators referred to, the air-dome pulsators to whose protection the present application is directed preferabl include means for the retention of a valve spring within or below a body which includes a noncircular portion, suitable for engagement by Each of the latter Other objects of the present invention may be -best appreciated from the followin descriptions of alternative embodiments t ereof, taken in connection with the appended claim and the accompanying drawing.

Fig. 1 is, for the most part, a vertical sectional view, only a small portion of a fuel pump, with the invention applied thereto, beingl shown.

Fig. 2 is a view taken Isimilarl to Fig. 1, but including additional parts an showing a more recent embodiment of the invention.

Fig. 3is a horizontal sectional view, taken pbstantially as indicated by the line 3 3 of Fig. 4 is a vertical sectional view, corresponding to the upper ri ht hand portion of Fig. 2, but showing an a ternative form.

Fig. 5 is a. horizontal sectional view taken substantially as indicated by the line 5 5 of Fi 4.

Figs. 6-9 are views similar to Figs. 4, but showing additional alternative forms.`

Referring first to Fig. 1, this view being taken from Fig. 4 of the mentioned application Ser. No. 254,490, pump body elements 10 and 11 are shown as cooperatlng in the re` tention. of a ump diaphragm 12, mani ulable by a diap ragm stem 13 1n a manner at is now well known; and the upper body element 11 is shown as providing not only a pump chamber 14 and an outlet passa 15, controlled by a valve 16, but an additlonal bubble-collecting chamber 17. This chamber communicates with a delivery openin 18 and also, by way of a throat 19, with an a1r chamber provided by a so-called cap or dome element 20. This is shown as integral with a body which merges into a flange 21, retained y screws 22, and as positioned above the valve 16 in such manner that bubbles of air or hydrocarbon vapors that may pass into or 288,755, filed June 17 1928; and, like the diaf orm within the chamber 17 can advance through the throat 19 into said air chamber.

In practice, it has now been found advantageous to employ throat openings somewhat different from that shown at 19, vand unnecessary to give the partitioning element 23 (whether or not this latter is secured, in somewhat the manner of a Welsh plug, in an anvergent. passa es or Fig. 7, a still hi nular channel 24) any downward convexity. v Considerations of utility and economy are accordingly favorable to the use of the one or another of the alternative forms which will now be successively described.

In Figs. 2 and 3, pump body elements 10a and 11a are shown as retaining a diaphragm 12a, reciprocable by guided stem 13a -a pump chamber 14a is shown as provided with an outlet passage 15a, controlled by a valve 16a. Thereabove, a bubble-collecting chamber 17 a is shown as communicating with both an outlet o ening 18a and a throat provided by a so-ca ed valve-plug body 23a. This body includes a non-circular or wrench-receiving portion` 24a, having an upwardly extending flange 25a, and a downwardly extending threaded portion 26a; an air-confining dome element'20a is shown as snugly fitting over the flange 25a, and as including a ateral flange which is seated in an annular channel 28a, wherein it may be additionally secured by soldering, as at 29a. To' permit rise of bubbles from the chamber 17a into the air chamber provided by the dome element 20a, a plurality of vertical or upwardly-inclined passages 30a, two being here shown, may communicate with a single upwardly expanding passa e 31a; and it is found to be important that t e passages 30a be of sufficient size, and suiciently vertical, to favor the mentioned rise of bubbles,the horizontal diameter thereof being preferably not less than that shown. For reasons that are not yet entirely clear, a tot-al cross-sectional area, in the passages 30a, amounting to approximately oneei hth of the inside horizontal sectional area o the dome 20a is found to give more satisfactory results than are obtainable by either a muc smaller or a much greater ratio than that mentioned. 1

In\ Figs. 4 and 5, three upwardly conducts 306 are shown as admitting bub les to an air chamber within the dome element 20?) and said dome element is shown as in'tertting in an upstanding exterior flange 256, no interior flange being provided;

In Fig. 6, a more rugged external flange 250 is shown as receiving and directly engaged by a dome element 20c, cylindrical in its lower part, in a manner favorable to a liberal and easy use of solder at 290; and in her flange 29d is interiorly provided, near t e upper end thereof, with a special channel 28d adapted to receive, with or without solder or crimping effects, peripheral portions of not only a dome element 20d but a special subsidiary throat element 32d.

This latter, if provided, may be formed, like the mentioned dome elements, of thin sheet metal, and it may be so spaced from a conical throat surface 31das to permit some entrapping of air in an intervening space 33d.

A similar effect may be obtained by the use of the form shown in Fig. 8,-in which an ample groove 38e is shown as provided externally of the flange 25e, to receive edge portions of both a dome element 20e and a subsidiary throat element 32e; and Fig. 9 will be seen to suggest not only enclosurel of edges of a dome element 20f and a throat element 32f between successively and oppositel deformed flanges 257c and 257" (solder eing optionally employed, as at 29f) but also the use of a lower end portion or downward prolongation of the throat element 32f (having any suitable upwardly convergent or other apertures 197, 191 and/or 19f and/or lugs 357 formed' therein) to provide a spring-retainer 6f,corresponding in function to the spring-retaining lingers 36, 36a, etc. of Figs. 1-8 inclusive. y

Several reference characters additional to those mentioned have been applied to Figs. 4-9 inc. consistently with the usage in preceding iigures; but the application of arrows to Fig. 2should not be understood to indicate any continuous or unidirectional flow of liquid through any of the mentioned domes. A vitally important discovery relied on in the present invention is the fact that by suitably positioning and proportioning air domes of the described types (the word air being herein used as inclusive of vapors), assuming bubble-collection chambers and throat passages .to be provided as described, a self-replenishing eifect may be obtained,- such as to provide an aircushion which serves for a pulsating effect in maintaining the onward flow of the pumped fuel, during intervals wherein the valves 16, 16a,etc.'are closed. When the exposure to absorption is too great, any confined air has been found to disappear into the fuel; when throat passages are two small or unfavorably disposed, bubbles which may form from previously absorbed or entrained air (and/or as a result of variations in pressure, in velocity and /or in temperature) may be carried, without segregation, onward through outlets 18,

18a, etc., into the delivery line, but self-re-i plenishment is nevertheless now found to be reliably obtainable by proper design along the lines indicated.

Within limits any desired plurality of convergently inclined or other openings 19, 19f, etc. may be provided in a suitable transverse partition element; and this element may be formed either, as in Fig. 1, by a separate Hat or convex or concave plate 23; or' by aA fixed horizontal element such as the artitions 37a 37 e,-shown as carrying iihe mentioned spring-retaining fingers 36a 36e; or by a downwardly-extending throat element such as 32d, 32e, or 32f but it is not considered desirable entirely to eliminate said partitioning element; and the use of a plurality of apertures 19, 19f, etc. is deemed advantageous as permitting ascent of bubbles through bodiments of proportioned as to admit one or more openings and a corresponding simultaneous other openin or openings.

Although t e foregoing description has included reference to several alternative emthe present invention, it should be understood not only that various features of said invention may be independently employed but also that numerous modifications, additional to those herein proposed, might easily be devised,all within the scope of the present invention. l

This application is a continuation in part of my application for fuel pump, Serial N o. 254,490, filed February 15, 1928.

I claim:

In a fuel pump ulsator of the air-dome type: a pulsator bo y element; and a bubblereceiving dome element secured thereto, one of sai-d elements having connected therewith a throat element which is so ositioned and bugbles into'said dome element,-the cross-sectional area within the throat of said throat element 'and that within said dome element being in substantially the ratio of 1 to 8.

In testimony whereof I ax m ABRAHAM M. B

signature. BITCH.

descent of liquid through an- 

